POTENTIAL OF PRECISION IRRIGATION WITH CENTER PIVOT IN GERMANY

摘要

In previous decades research and industry set the even distribution of water on a fi eld as agoal for irrigation technology. With today’s knowledge on soil heterogeneity and increasingfi eld sizes the need for site-specifi c water distribution becomes evident. These questionswere addressed in a four-year study in the Project “Aquarius &Klimzug-Nord” from 2010 to2013. For a preliminary evaluation of the site-specifi c irrigation technology mainly the watersaving and the additional capital requirements were used. During the projects, three differentcrops (sugar beets 2010, potatoes 2011, winter wheat 2012 and sugar beets 2013) could beharvested.Site-specifi c irrigation, requires details on the heterogeneity of fi elds to adjust the irrigationlevel to the local soil conditions, obtainable from an application map and determinationof management zones. In this study, the technical implementation was carried out with acircular irrigation machine with a special nozzle control with magnetic valves. Rotating baffl enozzles, mounted at six meter intervals, served for water distribution. A magnetic valve wasbuilt in front of each nozzle and were controlled electronically. To control the daily operationtime, the irrigation control model AMBER from the DeutscherWetterdienst (DWD, GermanMeteorological Service) was used as well as sensor techniques to monitor soil moistureand precipitation on the fi eld. This model offers a fi ve-day forecast for water need, whichallows a further targeted irrigation application. Due to changing weather conditions during thevegetation period in the tests from 2010 to 2013 different amounts of irrigation water wereused.